China's Minmetals Resources has ruled out making a fresh bid for Equinox Minerals of Australia after a Canadian firm topped its offer, ending Beijing's latest move on Australia's mining sector.

Canada's Barrick Gold, the world's biggest gold miner, said on Monday it had struck a deal to buy Equinox for $7 billion, well above the $6 billion Minmetals offered earlier this month.

Minmetals' bid for Equinox would have seen the biggest Chinese takeover of an Australian resources firm and could have created the 14th largest copper producer in the world.

"While we still consider the Equinox assets provide a good fit with MMR's strategy, the price offered by Barrick is above our most optimistic assessment of value," Minmetals chief executive Andrew Michelmore said in a statement to the Hong Kong stock exchange, where Minmetals is listed.

"Competing with Barrick at these prices would, in our view, be value-destructive for MMR's shareholders," he added.

Minmetals, China's largest metals trader, saw its shares plunge 7.88 per cent to 63 cents when it resumed trading on Tuesday afternoon after a suspension in the morning following news of Barrick's offer.

Barrick offered $7.98 per Equinox share in cash, which represents a 16 per cent premium over the per-share offer for Equinox proposed by Minmetals on April 4.

According to Barrick, the Equinox board of directors has "unanimously approved entering into the support agreement" and recommends Equinox shareholders accept the offer.

Earlier, Barrick Gold chief executive Aaron Regent told Bloomberg the mining giant had been watching the progress of Equinox for some time.

"I think our efforts accelerated when Equinox made an acquisition proposal to Lundin Mining, and then clearly intensified when Minmetals made the offer to Equinox," he said.

Equinox is listed in both Canada and Australia and has previously called the takeover bid by Minmetals "opportunistic" and "low-ball".

Minmetals' initial bid was the latest move by a Chinese state-owned firm to get a foothold in Australia's mining sector as the Asian powerhouse looks to tap the continent's huge natural deposits to feed its ever-growing economy.

However, Beijing's interest in its mining firms has sparked intense debate in Australia over whether to allow Chinese state-owned entities to increase their control over the country's resources.

MMR is 75 per cent owned by state-owned China Minmetals Corp.

Commodity prices have hit record highs over the past few months, fuelled by heavy demand from economic powers China and India and sparking a series of mergers and acquisitions in the industry.